AAP Reproductive System

Question 1

What is a newborn mammal known as?

Answer 1

• neonate

Question 2

What happens after fertilisation?

Answer 2

• sperm and ovum fuse to form a single-celled zygote
• zygote undergoes cell division to form an embryo
• an embryo becomes a fetus when major anatomical structures have formed
• known as a fetus until birth when it becomes a neonate

Question 3

How many pairs of chromosomes are there in dogs?

Answer 3

• 39 pairs

Question 4

What are chromosomes?

Answer 4

• DNA molecule packaged into thread-like structures in the nucleus of each cell

Question 5

What gender is XX?

Answer 5

• female

Question 6

What gender is XY?

Answer 6

• male

Question 7

What is mitosis?

Answer 7

• type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent cell
• typical form for ordinary tissue growth

Question 8

What is meiosis?

Answer 8

• type of cell division that results in daughter cells each with half the number of chromosomes of the parent cell
• sex cells (sperm and ovum) are produced this way
• ensures that the fertilized egg from the union of the sperm and ovum has the same number of chromosomes as the parent cell

Question 9

What are the accessory glands of the male reproductive system?

Answer 9

• seminal vesicle
• prostate gland
• bulbourethral gland
• ampullary gland

Question 10

What are the components of the duct system?

Answer 10

• epididymis
• vas/ductus deferens
• urethra

Question 11

What are the components of the external genitalia?

Answer 11

• penis

- scrotum

Question 12

Where are the testes located?

Answer 12

• located outside the abdomen

- in the lower portion of the anterior abdominal wall (inguinal region)

Question 13

What do the testes produce?

Answer 13

• sperm cells

- testosterone

Question 14

What is testosterone important for?

Answer 14

• influences the development of the sperm

- maintenance of male secondary sexual characteristics

Question 15

What is the epididymis?

Answer 15

• a highly convoluted/twisted duct behind the testis
• the tail of the epididymis continues as the vas deferens
• the sperm travels along the epididymis to the vas deferens and to the urethra

Question 16

What are the vas deferens?

Answer 16

• AKA ductus deferens
• function: to carry sperm quickly from the epididymis to urethra at ejaculation
• ampullary gland: the enlargement of the vas deferens just before it joins the urethra

Question 17

What are seminiferous tubules?

Answer 17

• single, long convoluted tube that connects testis with epididymis and the vas deferens
• the site sperm are produced
• sperm will travel through the epididymis to Vas deferens, along the efferent ducts
• interstitial cells produce androgens such as testosterone

Question 18

What do the accessory glands produce?

Answer 18

• alkaline fluid (including electrolytes, fructose and prostaglandins)
• these protect the sperm by counteracting the acidity of the female reproductive tract

Question 19

Which animals have seminal vesicles?

Answer 19

• all domestic animals except for the cat and dog

Question 20

Which animals have prostate gland?

Answer 20

• present in all domestic animals

- particularly large in the dog

Question 21

Which animals have bulbourethral glands?

Answer 21

• present in all domestic animals except carnivores

- not present in dogs

Question 22

What is the ampullary gland?

Answer 22

• the enlargement of the vas deferens just before it joins the urethra
• produces secretions into the semen

Question 23

What is the scrotum?

Answer 23

• skin pouch that houses the testes

Question 24

What is the function of the scrotum?

Answer 24

• helps regulate temperature of testes
• maintains testes at 3°C lower than normal body temperature to protect sperm viability
• two muscles (cremaster and the dartos) attached the scrotum to pull the scrotum close to the body when it is cold and relax when it is warm

Question 25

What is the penis?

Answer 25

- composed of muscle, erectile tissue, and connective tissue - rich blood supply and many sensory nerve endings - bulb of the glans is the enlargement toward the rear of the enlarged tip - in dogs, it reaches full size after ejaculation and remains clamped in placed by contraction of muscles surrounding the vagina

Question 26

Canine mating (1st and 2nd stage)

Answer 26

First stage - the male licks the vulva, the female stands with the tail to one side - the male mounts, dismounts, and turns - the male remains "tied" to the female after the first stage Second stage - ejaculation occurs - the male remains tied to the female for 5 mins to an hour - can be painful for the male as his penis is not in an ideal position